Recently, fluconazole, a new investigational anti-fungal agent, has experienced increased usage in patients with fungal infections and unable to receive amphotericin-B or in immune compromised patients in which susceptibility to infection is increased. A method of analysis utilizing HPLC with ultraviolet detection is currently being used in the CPRL to determine levels of fluconazole in plasma and urine. The method is sensitive, selective, and reliable. The results obtained are used in the determination of the pharmacokinetics of fluconazole. Another method of analysis used is a bioassay method developed by the drug company Pfizer (holds IND for fluconazole). In general bioassays are less selective and less sensitive when compared to an HPLC method of quantitation. In addition, the performance specifications at the lower concentration range are generally unacceptable. To obtain consistent and reliable data especially in the determination of the pharmacokinetics of a new investigational drug, it is imperative that the best available method be utilized. Consequently, a comparison of each method will be undertaken.